Often the reservoir rock is loosely consolidated, so that it tends to disintegrate and flow into the wellbore under the influence of hydrocarbon fluid flowing through the pore spaces.
Such inflow of rock particles, generally referred to as sand production, is a frequently occurring problem in the industry of hydrocarbon fluid production, as the produced sand particles tend to erode production equipment such as tubings and valves. Conventional methods of sand control include the installation of supporting perforated liners or screens, which allow the hydrocarbon fluid to pass but exclude the sand particles. Also, gravel packs are installed between the liners or screens and the wellbore wall to control sand production. Although such liners, screens and gravel packs have often been successfully applied, there are potential drawbacks such as clogging of the perforations, screens or gravel packs leading to diminished fluid production. Hence there is a need for an improved method of sand control.
U.S. Pat. Nos. 5,337,825 and 5,386,875 and U.S. patent application US 2003/0070805 disclose methods wherein stresses in the formation surrounding a wellbore are alleviated by means of shots or fractures with essentially parallel walls.